This invention is related to the field of stabilizing an organic polymeric material which is particularly to be protected against degradation by ultraviolet (UV) light, by incorporating a UV-stabilizer (UV-S); and, also to the deleterious effects of heat and oxygen by incorporating an antioxidant (AO).
More particularly, the compouds of this invention are relatively high molecular weight (mol wt) hindered amines formed by coupling a polyalkylenepolyamine ("PAPA") which provides the main chain, with a substituted 2-oxo-piperazinyl-triazine ("PIP-T") which provides the pendant groups on the N atoms of the PAPA main chain. These relatively high mol wt compounds are not only excellent photostabilizers but also provide excellent thermal stability.
The PIP-Ts which are disclosed in our U.S. Pat. No. 4,480,092 are formed by coupling a triazine having an appropriate leaving group, typically chlorine, with a polysubstituted piperazinone ("PSP") which is prepared by a ketoform synthesis. The ketoform synthesis (a) with a phase transfer catalyst is disclosed in U.S. Pat. No. 4,167,562; and, (b) without a phase transfer catalyst, in U.S. Pat. No. 4,466,915; pertinent portions of each of which patents are incorporated by reference thereto as if fully set forth herein. The PSP so formed is substituted at the N.sup.1 atom of the ring with an alkylamino substituent through which the PSP is subsequently linked to a triazine compound forming a PIP-T.
The PIP-Ts belong to a class of compounds known as multi-ringed triazine derivatives many of which exhibit desirable photostabilization (PS) activity, and more specifically, UV-S activity. However, each has one or more serious drawbacks which makes the one less desirable from a practical, utilitarian point of view than another having a less serious drawback. This reality dictates the unending search, even in the narrow field of multi-ringed triazine derivatives, for compounds with better UV-S activity, and results in discarding numerous derivatives with little or no activity, or those with desirable activity which are impractical to produce economically.
Prior art multi-ringed derivatives with UV-S activity are disclosed in U.S. Pat. Nos. 4,086,204; 4,0051,137; 4,108,829; French Pat. No. 2181 059; and, Japanese Pat. No. 51-4247; inter alia.
Certain cycloalkanes are also known to have UV-S activity, for example those disclosed in Ger. Offen. No. 2,315,042. Highly effective 2-keto-diazacycloalkanes are disclosed in U.S. Pat. Nos. 4,190,571; 4,207,228; substituted piperazinediones are disclosed in U.S. Pat. Nos. 3,919,234; and, 3,920,659.
In particular regard to our '092 patent, we found that a PSP which is distally linked to a triazine nucleus, forming the PIP-T, was unexpectedly effective not only for its UV-S activity, but also for its AO activity, as disclosed in our copending patent application Ser. No. 721,270 filed Apr. 9, 1985. We have now found that this dual activity is enhanced when the PIP-T is hung from a PAPA main chain to form compounds referred to as "pendant PIP-Ts".
The starting material for preparation of the '092 PIP-Ts was a branched chain PAPA which was reductively alkylated. The "branched chain PAPA" used in the preparation of the PSP which was subsequently attached to the triazine ring, was so termed because the C atom adjacent one primary amine group was disubstituted. After reductive alkylation, the compound obtained was cyclized by the ketoform synthesis to yield a PSP in which the N.sup.1 of the ring was substituted with an alkylamino chain and the N.sup.4 was unsubstituted. When the PIP-T was prepared by displacement of a Cl on the triazine ring, the bridge linking the triazine ring to the diazacycloalkane ring was a polymethylene chain (p methylene groups in the chain) none of which methylene groups was substituted, therefore "unbranched", hence the term "unbranched bridge" to characterize the PIP-Ts herein.